This invention relates to an improved walker for use by persons having physical disabilities.
More specifically, this invention relates to an improved and safer walker having wheel assemblies that can traverse rough surfaces and roll over small obstacles without wheel drag. In a preferred embodiment of this invention, braking means that are activated by a downward pressure applied by the user are also provided.
Walkers are commonly used as a support by many of the frail aged and other persons with physical disabilities while they are moving from place to place. One typical walker in use today consists of a generally rectangular, tubular frame having four legs and open at the rear. In some variations of that walker design, all four legs terminate in caps or buttons that slide along or otherwise engage the floor or other walking surface. The invalid walker described in U.S. Pat. No. 4,922,940 is of such design,
In another design variation, the two front walker legs are provided with wheels while the floor engaging ends of the rear legs terminate in a cap or button that slides along the floor or other surface as the user moves with the walker. The rear legs of this walker design tend to catch on minor surface irregularities and require the user to lift the rear of the walker to advance it, a task that often is difficult for many users. One approach to solving that problem has been to provide wheels on the rear walker legs as well as on the front. A full-wheeled walker is easier for a user to advance but also tends to be less stable, particularly when the user attempts to use the walker to aid or regain balance. That instability problem, in turn, has promoted efforts to provide a variety of braking systems that either act upon one or more of the walker wheels or rely upon an appendage to contact and drag along the floor or other walking surface. Examples of full-wheeled walkers that also incorporate a braking system include those described in U.S. Pat. Nos. 5,020,560 and 6,068,273.
None of the prior art walkers provide wheel means that can smoothly traverse small obstructions such as carpet edges, elevator doorways electrical cords, twigs and small branches, gravel, sidewalk irregularities and the like, and provide brake means that are intuitively and automatically operated by the user. This invention fills those needs.
The walker of this invention includes a generally rectangular three-sided frame, open at the back, and having a plurality of downwardly extending legs, each leg having a surface engaging wheel means at its lower end. Each of the forward, or front, wheel means comprise an obstacle traversing wheel assembly having at least one primary member that is rotatable about a central axis. At least four smaller secondary wheels of equal diameter are mounted on axles attached around the circumference of the primary member at fixed locations equidistant from each other and from the central axis. Each secondary wheel has a diameter that is greater than is the distance between adjacent wheel locations, and each is free to rotate about its axis. Each rear walker leg may have a wheel mounted at the lower end thereof and, in a preferred embodiment, each rear wheel includes a braking means that is activated by a downward pressure placed upon the walker frame by the user.
Hence, it is an object of this invention to provide a walker that rolls easily over small obstacles and is more maneuverable than are walkers of conventional design.
It is another object of this invention to provide a full-wheeled walker having brake means that are activated by a downward pressure applied to the walker frame by the user.
Other objects and advantages of this invention will become evident from a study of the following description and accompanying drawings.